The paper presents the results of microarc oxidation of porous aluminum made of alloys AlSi15, Д16 (D16) and AlMg6. According to research, on the surface of the sample, a composite oxide-ceramic coating is formed, consisting of mullite 3Al2O3‧2SiO2 and (or) various forms of aluminum oxide (α-, γ-Al2O3). It is shown that on the surface of porous aluminum, as well as in the pores of a cast sample, a coating is formed consisting of electropositive and electronegative sorption materials, aluminum oxides and aluminosilicates. Moreover, by changing the composition of the aluminum alloy and micro-arc oxidation modes, it is possible to control the phase composition of the coating being formed, which opens up the possibility of creating selective filter devices to retain either anionic or cationic inorganic compounds and microbiological objects.